# How does a fire start?

I know that fire in a few words is the exothermic reaction of a fuel with an oxidizing agent, but I can't fully understand what exactly happens to piece of wood when it is ignited. How do molecules start producing a flame? In other words, what is the chemistry behind the production of flame?

• Fire is about physics rather than chemistry. Sure, there is a chemical dimension to it, but it is quite trivial: $\ce{C + O2->CO2}$ (that is, if we burn coal; wood is somewhat more complicated, but whatever). May 23 '16 at 18:26
• related chemistry.stackexchange.com/questions/1254/… does not describe start of fire unfortunately May 23 '16 at 19:07
• chemistry.stackexchange.com/questions/44526/… is useful here May 23 '16 at 19:08
• May 23 '16 at 19:11
• This is a classic: youtube.com/watch?v=ITpDrdtGAmo (Always copy Feynman's answer) Jun 12 '16 at 23:03